Shania Twain stirs the crowd in Grant Park

Country pop star Shania Twain, on stage Sunday night for the first time in 3 1/2 years, began taping her NBC special in Grant Park's Hutchinson Field with a hit song, fireworks and a marriage proposal.

Three songs into her set, after singing "Man! I Feel Like A Woman!" "Up!" and "Honey, I'm Home," the four-time Grammy winner introduced Chicagoan James Hundt, who proposed to girlfriend Anneliesa Hahn after a lengthy introduction. Hahn responded with a near-tackling hug, and then said, "Absolutely," when coaxed to speak by Twain.

Twain, bellybutton showing between a bright-yellow top and black pants, then kicked into the rest of her set, including "She's Not Just a Pretty Face" and "When You Kiss Me."

"Thank you so much, Chicago! I tell you what, it's been great to be here in the city of Sammy Sosa," Twain said, her comment receiving a mix of cheers and boos.

According to NBC officials, "just over 50,000" people attended the free concert, sponsored by the Chicago Tribune and WUSN-FM 99.5. In August 2001, British rockers Radiohead inaugurated the venue, usually used for softball games, with a paid concert for more than 25,000 people.

With double the crowd, the taping of "Shania Twain: Up! Live in Chicago" was a much more cramped affair. According to concert officials, 30,000 people had arrived by 2 p.m., with fans forming a line as early as 10 a.m.

Despite their best efforts, security guards couldn't always keep narrow walkways clear. Long lines snaking out from portable toilets blended into the crowd. Handicapped seating also filled up by 7:15 p.m., according to a security guard.

Wearing sparkly, mirror ball-style cowboy hats, Colleen Sesten of Elmhurst, 13, and her friends sat on a red-and-white fleece blanket, one in a sea of thousands.

Despite a 40-minute late start, officials were pleased with the event.

"Actually, it's gone very, very smoothly," Laura Foxgrover, director of park services for the Chicago Park District, said near the end of the show. "This has been a great crowd, and people have been pretty well-behaved. It was a great way to showcase the city in a TV special."

Friday, NBC Entertainment President Jeff Zucker said: "Concerts with big stars do really well. We've had Cher and the Dixie Chicks, and they did great, and we expect the same out of Shania."

"Shania Twain: Up! Live in Chicago," a two-hour special, is scheduled to air Aug. 19 on NBC.